import { isFunction, isObject } from '@vben/utils';

const WILDCARD = '*';

function CamundaModdleExtension(eventBus) {
  // eslint-disable-next-line unicorn/no-this-assignment, @typescript-eslint/no-this-alias
  const self = this;

  eventBus.on('moddleCopy.canCopyProperty', (context) => {
    const parent = context.parent;
    const property = context.property;

    return self.canCopyProperty(property, parent);
  });
}

CamundaModdleExtension.$inject = ['eventBus'];

/**
 * Check wether to disallow copying property.
 */
CamundaModdleExtension.prototype.canCopyProperty = function (property, parent) {
  // (1) check wether property is allowed in parent
  if (isObject(property) && !isAllowedInParent(property, parent)) {
    return false;
  }

  // (2) check more complex scenarios

  if (is(property, 'camunda:InputOutput') && !this.canHostInputOutput(parent)) {
    return false;
  }

  if (
    isAny(property, ['camunda:Connector', 'camunda:Field']) &&
    !this.canHostConnector(parent)
  ) {
    return false;
  }

  if (is(property, 'camunda:In') && !this.canHostIn(parent)) {
    return false;
  }
};

CamundaModdleExtension.prototype.canHostInputOutput = function (parent) {
  // allowed in camunda:Connector
  const connector = getParent(parent, 'camunda:Connector');

  if (connector) {
    return true;
  }

  // special rules inside bpmn:FlowNode
  const flowNode = getParent(parent, 'bpmn:FlowNode');

  if (!flowNode) {
    return false;
  }

  if (
    isAny(flowNode, ['bpmn:StartEvent', 'bpmn:Gateway', 'bpmn:BoundaryEvent'])
  ) {
    return false;
  }

  return !(is(flowNode, 'bpmn:SubProcess') && flowNode.get('triggeredByEvent'));
};

CamundaModdleExtension.prototype.canHostConnector = function (parent) {
  const serviceTaskLike = getParent(parent, 'camunda:ServiceTaskLike');

  if (is(serviceTaskLike, 'bpmn:MessageEventDefinition')) {
    // only allow on throw and end events
    return (
      getParent(parent, 'bpmn:IntermediateThrowEvent') ||
      getParent(parent, 'bpmn:EndEvent')
    );
  }

  return true;
};

CamundaModdleExtension.prototype.canHostIn = function (parent) {
  const callActivity = getParent(parent, 'bpmn:CallActivity');

  if (callActivity) {
    return true;
  }

  const signalEventDefinition = getParent(parent, 'bpmn:SignalEventDefinition');

  if (signalEventDefinition) {
    // only allow on throw and end events
    return (
      getParent(parent, 'bpmn:IntermediateThrowEvent') ||
      getParent(parent, 'bpmn:EndEvent')
    );
  }

  return true;
};

// module.exports = CamundaModdleExtension;
export default CamundaModdleExtension;

// helpers //////////

function is(element, type) {
  return (
    element && isFunction(element.$instanceOf) && element.$instanceOf(type)
  );
}

function isAny(element, types) {
  return types.some((t) => {
    return is(element, t);
  });
}

function getParent(element, type) {
  if (!type) {
    return element.$parent;
  }

  if (is(element, type)) {
    return element;
  }

  if (!element.$parent) {
    return;
  }

  return getParent(element.$parent, type);
}

function isAllowedInParent(property, parent) {
  // (1) find property descriptor
  const descriptor =
    property.$type && property.$model.getTypeDescriptor(property.$type);

  const allowedIn = descriptor && descriptor.meta && descriptor.meta.allowedIn;

  if (!allowedIn || isWildcard(allowedIn)) {
    return true;
  }

  // (2) check wether property has parent of allowed type
  return allowedIn.some((type) => {
    return getParent(parent, type);
  });
}

function isWildcard(allowedIn) {
  return allowedIn.includes(WILDCARD);
}
